Avoid a loop in writeString and writePad by zeroing padding first.

Also add a benchmark to time the new improved writeString. Before
my change the bench took ~1.23ms and afterwards it takes ~.95ms.

Add some testing to ensure that writePad works properly.

TEST=Writer32Test, WriterBench

Review URL: https://codereview.appspot.com/6438045

git-svn-id: http://skia.googlecode.com/svn/trunk@4742 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 40 insertions, 0 deletions

diff --git a/bench/WriterBench.cpp b/bench/WriterBench.cpp
new file mode 100644
index 0000000000..2de653c374
--- /dev/null
+++ b/bench/WriterBench.cpp
@@ -0,0 +1,40 @@
+
+/*
+ * Copyright 2012 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBenchmark.h"
+#include "SkCanvas.h"
+#include "SkWriter32.h"
+
+class WriterBench : public SkBenchmark {
+public:
+    WriterBench(void* param) : INHERITED(param) {}
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return "writer";
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        static const char gStr[] = "abcdefghimjklmnopqrstuvwxyz";
+        static const size_t gLen = strlen(gStr);
+        SkWriter32 writer(256 * 4);
+        for (int i = 0; i < SkBENCHLOOP(800); i++) {
+            for (size_t j = 0; j <= gLen; j++) {
+                writer.writeString(gStr, j);
+            }
+        }
+    }
+
+private:
+    typedef SkBenchmark INHERITED;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+static SkBenchmark* fact(void* p) { return new WriterBench(p); }
+static BenchRegistry gReg(fact);